# Projectile Motion, speed of ball

Lara
I cant seem to get the right answer to this question so if someone could guide me through, please?

A ball is shot at a goal from a horizontal distance of 5.3m. The ball is released at an angle of 48 degrees to the horizontal and 1.2m below the height of the goal. What is the ballls speed?

thankyou

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Integral
Staff Emeritus
Gold Member
Did you give us all the information you have? I see no way, with the given information, to specify a single speed. Do you want the speed required to hit the goal?

Integral
Staff Emeritus
Gold Member
Assuming that you only need the projectile to be at the goal (5.3,1.2) you can get the speed with the following equations.

1. The components of the speed are Vx=VCos&Theta; and
Vy=VSin&Theta;

V is the speed, &Theta;=48deg

2. x(t) = Vxt with the condition that x(T)=5.3

3. y(t)= -gt2/2 + Vyt + Y with conditions y(0)=0 and Y(T)=1.2

This should be a nice start for you.